This invention relates to a method for enhancing the insulator reliability, and more particularly to a method for utilizing the rough insulator to enhance the metal-insulator-semiconductor reliability.
Because of the progress of the semiconductor industry, the thickness of the insulator of the semiconductor devices becomes thinner and thinner, and the thickness of the insulator might be less than 2 nm. When the devices are operated under the situation described above, the insulator will be degraded because of the electrical stress, and then stress induced leakage current (SILC) or soft breakdown caused by the electrical stress occurred.
Besides, among the new patterned devices which utilize tunneling current, such as metal insulator semiconductor light emitted diode (MISLED, Taiwanese Patent No. 456057) and metal insulator semiconductor photodetector (U.S. Pat. No. 6,268,615B1), both have to solve the problem about insulator reliability.
Because of the technical problems described above, the applicant keeps on carving unflaggingly to develop xe2x80x9cthe method for utilizing the rough insulator to enhance the metal-insulator-semiconductor reliabilityxe2x80x9d through wholehearted experience and research.
It is an object of the present invention to provide a method to increase the roughness of the interface between the insulator and the semiconductor to enhance the metal-insulator-semiconductor reliability.
It is another object of the present invention to provide a rough surface of the insulator to reduce the energy of the tunneling carriers, thus enhance the metal-insulator-semiconductor reliability and extend the time limit of the devices.
The present invention provides a method for utilizing a rough insulator to enhance metal-insulator-semiconductor reliability includes steps of: (a) providing a semiconductor substrate; (b) prebaking the semiconductor substrate under a relatively high vacuum to form a rough surface on the semiconductor substrate; and (c) growing an insulator on the semiconductor substrate to from a rough insulator and increase the metal-insulator-semiconductor reliability when the insulator is applied thereto.
Preferably, the semiconductor substrate is made of a material selected from a group consisting of silicon, germanium, silicon-germanium substrate and III-V group.
Preferably, the semiconductor substrate is made of a material selected from a group consisting of single-crystal silicon, polysilicon, amorphous silicon, and epitaxial growth.
Preferably, the semiconductor substrate is one of P-type and N-type.
Preferably, the step (b) further comprises a step of (b1) purifying the semiconductor substrate via introducing hydrogen.
Preferably, the step (b) is executed at a prebaking temperature ranged from 700 to 1000xc2x0 C., a prebaking pressure less than 10xe2x88x924 torr, and a prebaking time ranged from 1 to 60 minutes.
Preferably, the step (c) is executed by a growing method selected from a group consisting of furnace oxidation, rapid thermal oxidation, chemical vapor deposition, and anodic oxidation.
Preferably, the step (c) is formed by reacting with a material selected from a group consisting of gas, liquid, and solid.
Preferably, the insulator is a dielectric.
Preferably, the dielectric is selected from a group consisting of silicon dioxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (SiOxNy), and high-K materials.
In accordance with an aspect of the present invention, a method for utilizing a rough insulator to enhance metal-insulator-semiconductor reliability includes steps of: (a) providing a semiconductor substrate; (b) processing the semiconductor substrate by a chemical process to form a rough surface on the semiconductor substrate; and (c) growing an insulator on the semiconductor substrate to form a rough insulator and increase the metal-insulator-semiconductor reliability when the insulator is applied thereto.
Preferably, the chemical process in step (b) is a refined SC1 (Standard Clean-1, NH4OH, H2O2, H2O) chemical process (Q.-Y. Tone and U. Gosele. xe2x80x9cSemiconductor Wafer Bonding: Science and Technology.xe2x80x9d pp. 51-54, John Wiley and Sons, INC., 1999.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed descriptions and accompanying drawings, in which: